Khmelinskii Igor, Skatchkov Serguei N, Makarov Vladimir I
University of the Algarve, FCT, DQF and CEOT, 8005-139, Faro, Portugal.
Universidad Central del Caribe, Bayamón, PR, 00960-6032, USA.
Sci Rep. 2019 Jan 14;9(1):98. doi: 10.1038/s41598-018-36627-2.
Presently we report (i) excited state (exciton) propagation in a metal nanotrack over macroscopic distances, along with (ii) energy transfer from the nanotrack to adsorbed dye molecules. We measured the rates of both of these processes. We concluded that the effective speed of exciton propagation along the nanotrack is about 8 × 10 cm/s, much lower than the surface plasmon propagation speed of 1.4 × 10 cm/s. We report that the transmitted energy yield depends on the nanotrack length, with the energy emitted from the surface much lower than the transmitted energy, i.e. the excited nanotrack mainly emits in its end zone. Our model thus assumes that the limiting step in the exciton propagation is the energy transfer between the originally prepared excitons and surface plasmons, with the rate constant of about 5.7 × 10 s. We also conclude that the energy transfer between the nanotrack and the adsorbed dye is limited by the excited-state lifetime in the nanotrack. Indeed, the measured characteristic buildup time of the dye emission is much longer than the characteristic energy transfer time to the dye of 81 ns, and thus must be determined by the excited state lifetime in the nanotrack. Indeed, the latter is very close to the characteristic buildup time of the dye emission. The data obtained are novel and very promising for a broad range of future applications.
（i）激发态（激子）在宏观距离的金属纳米轨道中的传播，以及（ii）从纳米轨道到吸附染料分子的能量转移。我们测量了这两个过程的速率。我们得出结论，沿纳米轨道的激子有效传播速度约为8×10厘米/秒，远低于表面等离子体激元1.4×10厘米/秒的传播速度。我们报道，传输的能量产率取决于纳米轨道长度，表面发射的能量远低于传输能量，即被激发的纳米轨道主要在其端部区域发射。因此，我们的模型假设激子传播中的限制步骤是最初制备的激子与表面等离子体激元之间的能量转移，速率常数约为5.7×10秒。我们还得出结论，纳米轨道与吸附染料之间的能量转移受纳米轨道中激发态寿命的限制。实际上，测量到的染料发射特征积累时间远长于向染料的特征能量转移时间81纳秒，因此必须由纳米轨道中的激发态寿命决定。实际上，后者非常接近染料发射的特征积累时间。所获得的数据是新颖的，对未来广泛的应用非常有前景。
